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Asked

ARC Startup Error With Chromium Browser

I just received this error message after installing the latest version of ARC (the ARC application on my Windows 11 laptop). The error occurred immediately when I first tried to open ARC after installation. A second window opened and complained about my Google browser. What is going on here?

This happened when launching the ARC application on the PC (before connecting to any EZB or running any Robot Skills). The exception appears to come from CefSharp (the embedded Chromium browser component used by ARC). Here are the details I saw:

Timestamp: 2026-05-24 15:38:25 UTC
ARC Version: 2026.05.19.00
OS Version: Microsoft Windows NT 10.0.26200.0
Base Directory: C:\\Program Files (x86)\\Synthiam Inc\\ARC by Synthiam\\
=== Exception Information ===
Type: System.InvalidOperationException
Message: Cef.IsInitialized was false!.Check the log file for errors!. See https://github.com/cefsharp/CefSharp/wiki/Trouble-Shooting#log-file for details.
HResult: -2146233079
Source: CefSharp.WinForms
TargetSite: Void InitializeCefInternal()
StackTrace:
 at CefSharp.WinForms.ChromiumWebBrowser.InitializeCefInternal() in C:\\projects\\cefsharp\\CefSharp\\Internals\\Partial\\ChromiumWebBrowser.Partial.cs:line 532
 at CefSharp.WinForms.ChromiumWebBrowser.InitializeFieldsAndCefIfRequired() in C:\\projects\\cefsharp\\CefSharp.WinForms\\ChromiumWebBrowser.cs:line 336
 at CefSharp.WinForms.ChromiumWebBrowser.OnHandleCreated(EventArgs e) in C:\\projects\\cefsharp\\CefSharp.WinForms\\ChromiumWebBrowser.cs:line 593
 at System.Windows.Forms.Control.WmCreate(Message& m)
 at System.Windows.Forms.Control.WndProc(Message& m)
 at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
 at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
 at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

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